fix(elements): Add tag for Expression Tree to generate as a class in old React wrappers.

Author: skrustev

projects/igniteui-angular/src/lib/data-operations/filtering-expressions-tree.ts

@@ -8,6 +8,7 @@ export enum FilteringExpressionsTreeType {
     Advanced
 }
 
+/* marshalByValue */
 export declare interface IExpressionTree {
     filteringOperands: (IExpressionTree | IFilteringExpression)[];
     operator: FilteringLogic;